DOE Cold Climate Heat Pump Challenge: The Models That Made It to Market

OAK RIDGE, Tenn. — The Department of Energy’s Residential Cold Climate Heat Pump Technology Challenge has moved from the lab to showrooms. Eight manufacturers finished a full winter of monitored field testing, and by the 2026 heating season products from Carrier, Bosch and Lennox are on the market, with York and Trane following. If you heat a home where January regularly dips below zero, the challenge gives you a short list of what to ask for.

What happened

DOE launched the challenge in 2021 with the EPA and Natural Resources Canada. The target was a centrally ducted, electric-only heat pump between 24,000 and 65,000 BTU/h (2 to 5.4 tons) that could carry a cold-climate home without leaning on electric resistance strips. The specification required 100 percent of rated 47°F heating capacity at 5°F, a coefficient of performance (COP, heat delivered per unit of electricity) of at least 2.1 to 2.4 at 5°F depending on size, a seasonal HSPF2 of 8.5 in DOE’s coldest climate region, staged auxiliary heat and a refrigerant with a GWP no higher than 750. An optional second tier asked for continued compressor operation at −15°F.

The original 2021 partner list included Mitsubishi Electric and LG; Bosch joined later, and the eight that completed the field phase were Bosch, Carrier, Daikin, Johnson Controls, Lennox, Midea, Rheem and Trane Technologies. Prototypes went through lab testing at Oak Ridge National Laboratory in 2022 and 2023, then into 23 homes across 10 states and two Canadian provinces, where Pacific Northwest National Laboratory collected a full year of data at each site. DOE’s summary: the units reliably heated the homes with little help from backup elements, even in the coldest stretches. Trane, for example, reported its Boise, Idaho test unit ran on backup strips about 10 percent of the time across two winters.

Commercial products followed at different speeds. Bosch was first, launching the IDS Ultra in October 2024; it holds 100 percent of rated capacity down to 5°F and operates to −13°F. Carrier took orders for its Infinity Variable-Speed Ultimate Cold Heat Pump with Greenspeed Intelligence starting in 2024 and formally completed the challenge in June 2025, rating the unit at 100 percent capacity at 0°F with operation to −23°F. Lennox brought the Dave Lennox Signature Collection SL22KLV to market in 2025: 2 to 5 tons, up to 21.1 SEER2 and 10.5 HSPF2, R-454B refrigerant and rated operation to −20°F. Johnson Controls says its York YHV Ultra-Premium Cold-Climate Heat Pump will replace the YZV, with manufacturing beginning in late 2026. Trane, whose prototype ran to −23°F in testing, has said it expects its production cold-climate model to be available in 2026; a model name had not been published when we checked. Rheem’s challenge unit beat the 5°F COP requirement by 5 percent in DOE testing, and its Endeavor line already includes ENERGY STAR Cold Climate models. Daikin and Midea had not, as far as we can confirm, named a challenge-derived model at the time of writing.

Why it matters

Until recently, “cold-climate” was a marketing term with soft edges. The challenge put a number on it: full capacity at 5°F, verified by a national lab, then confirmed in real houses. That matters because a heat pump that loses 30 or 40 percent of its output at 5°F must be oversized for summer or paired with a large electric backup, either of which raises cost and hurts comfort. A unit that holds capacity can be sized to the house.

The challenge also settled the does-it-work-below-zero question for ducted systems. Mini-splits from Mitsubishi and Fujitsu have offered strong sub-zero performance for years, as our Mitsubishi Hyper-Heating review explains, but many homes with existing ductwork wanted a central unit. There are now several.

None of these products are cheap. For a challenge-class ducted system, a typical installed price (2026, before incentives) runs roughly $14,000 to $25,000, higher for large homes. With the federal 25C credit gone for 2026, state and utility cold-climate rebates carry more of the load, and many of those programs key on the NEEP list described below.

What homeowners should do

• Start with the NEEP list. Northeast Energy Efficiency Partnerships maintains the Cold Climate Air Source Heat Pump (ccASHP) product list, which builds on the ENERGY STAR Cold Climate criteria (COP of at least 1.75 at 5°F and at least 70 percent of 47°F capacity at 5°F) and publishes capacity and COP at 47°F, 17°F and 5°F for every listed model. Most northern rebate programs require a listed model.
• Prefer units at or above the challenge bar. Look for 100 percent capacity at 5°F and a COP of 2.0 or better at 5°F. Anything rated to operate at −15°F or lower gives you margin for a polar-vortex week.
• Ask about the backup heat strategy. Challenge units stage electric strips in small increments. Make sure the installer sets the lockout and balance-point settings, or the strips can run more than they need to.
• Compare the leading models. Our Carrier Infinity 24 review, Bosch IDS review and Lennox SL25XPV review cover current flagships from three challenge participants, and our best heat pumps for cold climates guide ranks them alongside ductless options.
• Understand the ratings. SEER2 measures summer, HSPF2 measures an average winter, and COP at 5°F measures the day you actually care about. Weight them accordingly.